JP6513658B2 - Differential - Google Patents

Description

  The present invention relates to a differential of a new mechanism that distributes the rotational force of an input plate to a first output shaft and a second output shaft coaxially relatively rotatably arranged via a cycloid reduction mechanism or a trochoid reduction mechanism, In particular, the present invention relates to one suitably used as a differential device that allows a rotational difference between left and right or front and rear drive wheels of a vehicle.

  In a conventional differential gear using a bevel gear, not only the generation of rattling noise can not be avoided as a characteristic of bevel gear meshing, but the number of simultaneously meshing teeth is only a part of all the teeth, so only some of the teeth are There is room for improvement in terms of strength performance and durability performance due to the burden of torque.

  Then, although the differential device which used the ball mechanism like patent document 1 is known, with this thing, a plurality of balls are held slidably by a plurality of radial long holes of a center plate, and these balls The balls are rollably engaged with the transmission grooves of the left and right disk plates so that the balls are in contact with the transmission grooves of the left and right grooves. At the same time, the friction resistance of the ball at that time becomes a large power loss, which adversely affects the fuel efficiency performance of the engine.

  In addition, although a cycloid transmission mechanism as in the prior art 2 is also known, this is a simple transmission mechanism and is difficult to apply as a differential gear.

Japanese Patent Application Laid-Open No. 8-170705 Japanese Patent Application Laid-Open No. 2003-172419

  The present invention has been made in view of such circumstances, and it is intended to maintain equal torque distribution equally divided to the left and right output shafts, and to distribute torque equally, and to make a difference between two output shafts as when the vehicle is turning. A differential that enables differential rotation such as increasing the rotation speed of one output shaft equal to the reduction of the rotation speed of the other output shaft without changing the rotation speed of the input member when applying rotation An object of the present invention is to provide a device without using a bevel gear and a center plate with radial slots as in a conventional differential device by using a two-stage cycloid reduction mechanism or a trochoid reduction mechanism.

  In order to achieve the above object, according to the present invention, a first output shaft and a second output shaft are arranged so as to be relatively rotatable on the first rotation axis through a cycloid reduction mechanism or a trochoid reduction mechanism. A first differential plate disposed adjacent to one side of the input plate rotating about the first rotation axis, and the first differential plate A second differential plate disposed adjacent to one side opposite to the input plate; and an eccentric shaft rotatably supporting the first differential plate about a second rotation axis eccentric to the first rotation axis; The eccentric shaft is integrally rotatably connected to the first output shaft, and the second differential plate is integrally rotatably connected to the second output shaft, and the first differential of the input plate Hypocycloid curve or hypotrochoid of the first wave number on one side facing the plate A first hypo-groove portion extending in a circumferential direction along a line is formed, and the epicyclic curve or epitrochoid curve of the second wave number is formed on one side of the first differential plate opposite to the input plate. A first epi-groove portion extending in the circumferential direction is formed, and a plurality of first rolling elements are sandwiched between the two groove portions at a portion where the both groove portions overlap with each other, and the first differential plate On the other side opposite to the second differential plate, a second hypo groove portion extending in the circumferential direction along the hypocycloid curve or the hypotrochoid curve of the third wave number is formed, and the second differential plate of the second differential plate A second epi groove, which extends circumferentially along an epicycloid curve or an epitrochoid curve of a fourth wave number, is formed on one side opposite to the differential plate, and both of the two groove portions overlap each other at both portions. A plurality of second between striations A moving body is held, the first wave number is 8, the second wave number and the third wave number are both 6, the fourth wave number is 4, or the first wave number and the fourth wave number are It is a first feature that the both are six, the second wave number is four, and the third wave number is eight.

  Further, according to the present invention, in addition to the first feature, a differential case supported rotatably around the first rotation axis on a transmission case of a car is fixed to the input plate and the input plate so as to make the first difference. According to a second feature of the present invention, a moving plate, a cover covering the eccentric shaft and the second differential plate are provided.

  According to the present invention, in addition to the second feature, the eccentric shaft projects in a radial direction from a central shaft portion rotating around the first rotation axis, and the first differential plate. And an eccentric shaft portion rotatably supported about the second rotation axis, and the central shaft portion is connected to the first output shaft through a central portion of the input plate, the second differential plate A third feature of the present invention is that it has a central axis that rotates around the first rotation axis, and the central axis passes through a central portion of the cover and is connected to the second output shaft.

  Further, according to the present invention, in addition to the third feature, the hollow cylindrical first and second shafts are rotatably supported by the transmission case on the first rotation axis and the input plate and the cover. A center portion of the eccentric shaft is rotatably supported on an inner periphery of the first shaft portion via a first bearing, and the center axis of the second differential plate is A central shaft portion of the eccentric shaft opposite to the first shaft portion is rotatably supported on the inner periphery of the second shaft portion via a second bearing, and the one side surface of the second differential plate is A fourth feature is to be fitted into the formed circular recess through a third bearing.

  In addition to the first to fourth features of the present invention, the fifth feature is that a lightening portion is formed at a central portion of the one side surface of the input plate.

  Further, in the present invention, in addition to the first feature, a lightening portion is formed at a central portion of the one side surface of the input plate, and the first difference which rotates around the first rotation axis in the lightening portion. A sixth feature of the present invention is that a balancer connected to the eccentric shaft is arranged to rotate around the first rotation axis at a phase 180 degrees out of phase with the center of gravity of the moving plate.

  Further, in addition to the sixth feature, the present invention is the first rotation when viewed from the projection plane orthogonal to the mass of the first differential plate as M1, the mass of the balancer as M2, and the first rotation axis. Assuming that the distance from the axis to the center of gravity of the first differential plate is e1, and the distance from the first rotation axis to the center of gravity of the balancer is e2, | M1 × e1-M2 × e2 | <M1 × e1 / A seventh feature is that the value is 100.

  Further, in the present invention, in addition to the sixth or the seventh feature, the eccentric shaft protrudes from the central shaft in a radial direction from the central shaft rotating around the first rotation axis, and the first difference And an eccentric shaft portion rotatably supporting the movable plate about the second rotation axis, and the balancer extends radially outward from the outer periphery of the central shaft portion in a direction opposite to the projecting direction of the eccentric shaft portion. An eighth feature of the present invention is an arm portion and a weight portion connected to a tip of the arm portion, wherein an outer periphery of the weight portion is formed in an arc shape along an inner periphery of the lightening portion.

  Furthermore, in addition to the eighth feature, the present invention is characterized in that the balancer is integrally formed with the central shaft portion.

  Further, according to the present invention, in addition to any of the sixth to ninth features, a differential case rotatably supported around the first rotation axis on a transmission case of a car is fixed to the input plate and the input plate. According to a tenth aspect of the present invention, there is provided a tenth feature, wherein the first differential plate, the eccentric shaft, the balancer, and a cover covering the second differential plate are provided.

  Still further, according to the present invention, in addition to any one of the sixth to tenth features, the meat of the input plate is interposed between the first differential plate and the central portion of the one side surface of the second differential plate. A cylindrical sub-thinned portion opposed to the cut-out portion is formed, and in the sub-thinned portion, the phase is 180 degrees out of phase with the center of gravity of the first differential plate rotating around the first rotation axis. An eleventh feature is that a sub-balancer connected to the eccentric shaft is disposed to rotate around a first rotation axis.

  Furthermore, in addition to any one of the first to eleventh features, the present invention is characterized in that the first differential plate is configured to include a pair of rotatable plates that are mutually connected and integrally rotatable. It is the feature of

  According to the first aspect of the present invention, the cycloid reduction mechanism or trochoid reduction mechanism constituting the differential device is disposed adjacent to one side of the input plate rotating about the first rotation axis, A second differential plate disposed adjacent to one side opposite to the input plate of the first differential plate, and the first differential plate rotatably rotatable about a second rotation axis eccentric to the first rotation axis And an eccentric shaft for supporting, the eccentric shaft being integrally rotatably connected to the first output shaft, and the second differential plate being integrally rotatably connected to the second output shaft; And a first hypo groove portion circumferentially extending along a hypocycloid curve or a hypotrochoid curve of a first wave number is formed on one side surface facing the first differential plate, and an input plate of the first differential plate The second wave number epicycloidal curve or epi A first epi groove portion extending in a circumferential direction along the curve is formed, and a plurality of first rolling elements are held between the two groove portions at a portion where the both groove portions overlap each other, and a first differential plate On the other side opposite to the second differential plate, a second hypo groove portion circumferentially extending along the hypocycloid curve or the hypotrochoid curve of the third wave number is formed, and the second differential plate of the second differential plate A second epi groove, which extends circumferentially along an epicycloid curve or an epitrochoid curve of a fourth wave number, is formed on one side opposite to the differential plate, and both of the two groove portions overlap each other at both portions. A plurality of second rolling elements are held between the groove portions, and the first to fourth wave numbers have a first wave number of 8, the second wave number and the third wave number are both 6, and a fourth wave number is 4 or both the first wave number and the fourth wave number are 6 Since the second wave number is 4 and the third wave number is 8, when the input plate is rotated, the first and second outputs are not provided when the rotational speed difference is not given between the first and second output shafts. When the shaft can be integrally rotated with the input plate and the rotation speed difference is provided between the first and second output shafts, the increase in the rotation speed of one output shaft is the decrease in the rotation speed of the other output shaft Differential rotation, etc. can be realized without using bevel gears or center plates with radial slots.

  That is, in the differential gear having the above configuration, when the input plate is fixed and the first output shaft is rotated, the first differential plate connected to the first output shaft via the eccentric shaft is the first output shaft. In this case, a first hypo groove formed on one side of the input plate and a first epi groove formed on one side of the first differential plate are attempted to rotate about the first rotation axis. Since the plurality of first rolling elements are held between the two, the first differential plate revolves around the first rotation axis of the first output shaft while rotating about the second rotation axis of the eccentric shaft. At this time, between the second hypo groove formed on the other side surface of the first differential plate and the second epi groove formed on one side surface of the second differential plate, a plurality of second Since the moving body is held, when the first differential plate revolves and rotates due to the rotation of the first output shaft, the second differential plate is interlocked with it and the first differential plate is centered on the first rotation axis of the second output shaft. The output shaft rotates at a rotational speed different from that of the output shaft, and the rotation of the first output shaft is shifted and transmitted to the second output shaft. Therefore, when the input plate is rotated while the first and second output shafts are rotating in this way, the number of rotations of the input plate is added to the number of rotations of each output shaft for the first and second output shafts. Will be output.

  The reduction ratio when transmitting the rotation of the first output shaft to the second output shaft using such a reduction mechanism is the first wave number Z1, the second wave number Z2, the third wave number Z3, the fourth In the present invention, Z1 = 8, Z2 = Z3 = 6, Z4 = 4, or Z1 is represented by [1-{(Z1 × Z3) / (Z2 × Z4)}] when the wave number is Z4. Since Z4 = 6, Z2 = 4, and Z3 = 8, the speed reduction ratio can be -1 in any case. This means that when the input plate is fixed and one output shaft is rotated n times, the other output shaft is rotated n times in the opposite direction. When the number of rotations of the output shaft is increased by n rotations from the number of rotations of the input plate, the differential rotation is performed such that the number of rotations of the other output shaft is decreased by n rotations from the number of rotations of the input plates It will be. In the case where the number of rotations of one output shaft is not increased more than the number of rotations of the input plate, that is, when there is no differential rotation on the first and second output shafts, the number of rotations of these first and second output shafts Since it becomes equal to the number of rotations of the input plate, it is natural that the first and second output shafts integrally rotate with the input plate in that case. Moreover, as described later, by setting the first to fourth wave numbers to the numerical value, equal torque distribution of the first and second output shafts becomes possible, so equal torque distribution and equal differential rotation are possible. A differential mechanism can be realized without using bevel gears or center plates with radial slots.

  As described above, according to the first feature of the present invention, since the differential mechanism can be configured by the cycloid reduction mechanism or the trochoid reduction mechanism, the axial length of the differential mechanism can be suppressed to make it compact. Moreover, there is no generation of rattling noise as in the case of using a bevel gear, and a radial long holed center plate causing sliding of the rolling elements becomes unnecessary, so the power from the input plate can be efficiently used for the first and second output shafts. I can communicate well. Still further, all the first and second rolling elements are torqued between the first hypo groove and the first epi groove and between the second hypo and the second epi groove. Is distributed and transmitted, so that the torque transmitted by each rolling element can be reduced, and the strength performance and durability performance of each rolling element are improved.

  According to a second feature of the present invention, a differential case rotatably supported around a first rotation axis on a transmission case of a car is fixed to the input plate and the input plate, and a first differential plate is provided. Since it is composed of a cover that covers the eccentric shaft and the second differential plate, a difference that allows a two-stage transmission mechanism using a cycloid reduction mechanism or a trochoid reduction mechanism to have a difference in rotation between the left and right or front and rear drive wheels of the vehicle It can be suitably used as a moving device. Moreover, since the input plate constitutes a part of the differential case, the number of parts can be reduced, and the first and second differential plates and the eccentric shaft are accommodated in the differential case. The device can be made compact without significantly changing the configuration of the conventional differential.

  Further, according to a third feature of the present invention, the eccentric shaft projects radially from the central shaft portion rotating around the first rotation axis, and from the central shaft portion, and the first differential plate is moved to the second rotation axis An eccentric shaft rotatably supported around the central shaft, the central shaft being connected to the first output shaft through the central portion of the input plate, and the second differential plate being rotated about the first rotation axis And the central shaft is connected to the second output shaft through the central portion of the cover, so that the eccentric shaft portion of the eccentric shaft having the central shaft portion penetrated to the central portion of the input plate is (1) An eccentric shaft and the first differential plate are supported only by supporting the differential plate and disposing the second differential plate with the central axis penetrating through the center of the cover outside the first differential plate. The second differential plate can be easily assembled in the differential case.

  According to a fourth feature of the present invention, the input plate and the cover have hollow cylindrical first and second shaft portions rotatably supported by the transmission case on the first rotation axis, A central shaft portion of the eccentric shaft is rotatably supported on an inner periphery of the first shaft portion via a first bearing, and a central axis of a second differential plate is a second shaft on an inner periphery of the second shaft portion. A central shaft portion of the eccentric shaft opposite to the first shaft portion is rotatably supported via a bearing, via a third bearing in a circular recess formed on one side surface of the second differential plate. Since it is fitted, smooth relative rotation of the eccentric shaft and the second differential plate in the differential case can be ensured by only the first to third bearings.

  Further, according to the fifth feature of the present invention, since the lightening portion is formed at the central portion of one side surface of the input plate, the material of unnecessary portions of the input plate is reduced to reduce the cost of the differential device. The weight of the differential can be reduced.

  Further, according to a sixth aspect of the present invention, a lightening portion is formed at a central portion of one side surface of the input plate, and in the lightening portion, the center of gravity of the first differential plate rotating around the first rotation axis. Since the balancer connected to the eccentric shaft is arranged to rotate around the first rotation axis in a phase 180 degrees out of phase, the unbalanced rotation of the first differential plate can be canceled by the balancer, and the first differential can be obtained. Vibration due to centrifugal force due to the amount of imbalance of the plate and the generation of noise associated therewith can be effectively suppressed. Moreover, by arranging the balancer in the lightening portion of the input plate, the balancer can be compactly arranged between the first differential plate and the input plate, and the material of the unnecessary portion of the input plate is reduced by the lightening portion. As a result, the cost of the differential can be reduced and the weight of the differential can be reduced.

  Further, according to the seventh aspect of the present invention, the difference between the imbalance amount of the first differential plate and the imbalance amount of the balancer is smaller than one hundredth of the imbalance amount of the first differential plate. Since the imbalance amount of the first differential plate and the imbalance amount of the balancer can be made substantially equal, the mass and the eccentricity of the balancer with respect to the mass and the eccentricity of the first differential plate can be optimized.

  Further, according to an eighth aspect of the present invention, the eccentric shaft projects radially from the central shaft portion rotating around the first rotation axis and from the central shaft portion, and the first differential plate is moved to the second rotation axis An eccentric shaft portion rotatably supported around the arm portion, the balancer extending radially outward from an outer periphery of the central shaft portion in an arm portion extending in a direction opposite to the projecting direction of the eccentric shaft portion; The weight portion has a continuous weight portion, and the outer circumference of the weight portion is formed in an arc shape along the inner circumference of the lightening portion and is adjacent to the inner circumference of the lightening portion. The center of gravity of the balancer can be separated from the rotation center of the balancer close to the inner circumferential surface of the lightening portion, and an increase in weight due to the balancer can be suppressed.

  Further, according to the ninth aspect of the present invention, since the balancer is integrally formed with the central shaft portion, the positional relationship between the balancer and the eccentric shaft does not change in any case, and the balancer always has the first difference. It can be rotated at a phase that is 180 degrees out of phase with the center of gravity of the moving plate.

  According to a tenth aspect of the present invention, a differential case rotatably supported around a first rotation axis on a transmission case of a car is fixed to the input plate and the input plate, and a first differential plate is provided. Since the cover covers the eccentric shaft, the balancer and the second differential plate, the two-stage transmission mechanism using the cycloid reduction mechanism or trochoid reduction mechanism allows the difference in rotation between the left and right or front and rear drive wheels of the vehicle. And the input plate constitutes a part of the differential case, so that the number of parts can be reduced. In addition, since the first and second differential plates and the eccentric shaft can be compactly accommodated in the differential case by arranging the balancer at the lightening portion of the input plate, the differential device for automobile of such a new mechanism can be obtained. It can be formed without largely changing the configuration of the conventional differential device.

  Further, according to an eleventh aspect of the present invention, at a central portion of one side surface of the second differential plate, a cylindrical sub-thinned portion facing the lightly-extracted portion of the input plate across the first differential plate is provided. An auxiliary shaft connected to the eccentric shaft so as to rotate around the first rotation axis in a phase out of phase with the phase of the center of gravity of the first differential plate rotating around the first rotation axis within the sub thinning portion; Since the balancer is arranged, the unbalanced rotation of the first differential plate can be balanced from the left and right by the balancer and the sub-balancer arranged on both sides of the first differential plate, and the imbalance of the first differential plate While being able to suppress generation | occurrence | production of the vibration resulting from the centrifugal force by quantity further effectively, the mass of each of a balancer and a sub-balancer can be made small, and they can be compacted.

  Further, according to a twelfth feature of the present invention, since the first differential plate is configured to include the pair of rotatable plates connected to each other and integrally rotatable, the first differential plates can be divided into two rotatable plates. Can be divided into Therefore, for example, since it is possible to adopt a manufacturing method in which two rotary plates each having a groove portion on one side are formed by forging or the like and then connected, it is possible to form the groove portion excellent in strength quickly and easily. Manufacturing workability is increased. Further, since the sizes of the surface of the first differential plate facing the input plate and the surface of the first differential plate facing the second differential plate can be set independently of each other, the second wave number is 4 and the third wave number is 8 In any case, the freedom of design is improved.

  Although the first and second rolling elements correspond to first and second rolling balls 18 and 19 in the embodiment of the present invention described later, these rolling elements need to be rolling balls in particular. For example, it may be roller-shaped.

FIG. 1 is a longitudinal front view of a differential according to a first embodiment of the present invention when Z1 = 8, Z2 = Z3 = 6, and Z4 = 4. First Embodiment FIG. 2 is a schematic view of the differential of FIG. First Embodiment FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. First Embodiment FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. First Embodiment FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. First Embodiment FIG. 6 is a skeleton diagram of the differential of FIG. First Embodiment FIG. 7 is a skeleton diagram of the differential gear according to the first embodiment of the present invention when Z1 = Z4 = 6, Z2 = 4 and Z3 = 8. First Embodiment FIG. 8 is a longitudinal front view of a differential gear according to a second embodiment of the present invention. Second Embodiment FIG. 9 is a longitudinal front view of a differential gear according to a third embodiment of the present invention. Third Embodiment

1 · · · Transmission case 2 · · · Differential case 3 · · · First differential plate 3a · · · One side surface 3b of the first differential plate · · · Other side surface 3c of the first differential plate · · · · Rotating plate (first rotating plate)
3d ・ ・ ・ rotary plate (second rotary plate)
4 second differential plate 4a one side 4b of the second differential plate 4b central axis 4c of the second differential plate 4c circular recess 5 of the second differential plate 5 · · Eccentric shaft 5a · · · Central shaft portion 5b · · · Eccentric shaft portion 6 · · · First shaft 7 · · · Input plate 7a · · · One side surface 7b of the input plate · · · Meat of the input plate Extraction part 8 ... 2nd axis 9 ... ... Cover 13 ... Balancer 13a ... Arm part 13b ... Weight part 15 ... 1st output shaft 16 ... 2nd output shaft 18 ... · First rolling element (first rolling ball)
19 ··· Second rolling element (second rolling ball)
20 ... secondary balancer E1 ... first epi groove E2 ... second epi groove G1 ... center of gravity G2 of the first differential plate G2 ... center of gravity H1 of the balancer H1 ... first Hypo groove groove H2 ... second hypo groove groove X1 ... first rotation axis X2 ... second rotation axis Z1 ... first wave number Z1 of the first hypo groove groove ... second Second wave number Z3 of epi-grooves of the third part · · · third wave number Z4 of the second hypo-grooves · · · fourth wave number of the second epi-lines

  Embodiments of the present invention will be described below based on the attached drawings.

First embodiment

  First, a first embodiment in which the differential device of the present invention is used as a differential device of a vehicle will be described based on FIGS. 1 to 7.

  In FIG. 1, a differential gear D housed in a transmission case 1 of a vehicle includes a differential case 2 and first and second differential plates 3 and 4 and an eccentric shaft 5 housed in the differential case 2. ing. The differential case 2 has a circular input plate 7 having a hollow cylindrical first shaft 6 and a hollow cylindrical second shaft 8 aligned on the same axis as the first shaft 6, and also has a first and second difference. The first and second shafts 6, 8 are bearings 10, 10, respectively, and cover the moving plates 3, 4 and the eccentric shaft 5 and cover the outer periphery thereof with bolts B1 at the outer peripheral portion of the input plate 7. 'Is rotatably supported on the transmission case 1 via the first rotation axis X1.

  The first differential plate 3 is disposed adjacent to one side of the input plate 7 in the differential case 2, and the second differential plate 4 is a first differential plate 3 on the opposite side to the input plate 7 in the differential case 2. Adjacent to one side of the

  Referring also to the schematic view of FIG. 2, the eccentric shaft 5 has a central shaft 5a and an eccentric shaft 5b radially projecting from the central shaft 5a, and the central shaft A second rotation 5a is rotatably supported around a first rotation axis X1 on an inner periphery of the first shaft 6 via a first bearing 11 and is eccentric from the first rotation axis X1 by C. The eccentric shaft portion 5b having the axis X2 rotatably supports the first differential plate 3 via the needle bearing 12 on the outer periphery thereof, thereby making the first differential plate 3 around the first rotation axis X1. It is possible to make it revolve and rotate around the second rotation axis X2.

  In the second differential plate 4, the central shaft 4 b provided on the side surface on the side of the second shaft 8 of the second differential plate 4 penetrates the central portion of the cover 9 and the second periphery of the second shaft 8. By being rotatably supported via the bearing 11 ', it can be rotated relative to the second shaft 8 about the first rotation axis X1, and moreover, the first differential plate 3 of the second differential plate 4 can be provided. The eccentric shaft 5 and the central shaft portion 5a of the eccentric shaft 5 on the opposite side to the first shaft 6 are fitted into the circular recess 4c formed on the side surface via the third bearing 11 ′ ′. The second differential plate 4 can be relatively smoothly rotated within the differential case 2 only by the first to third bearings 11 to 11 ′ ′.

  Referring also to FIG. 4 which is a cross-sectional view taken along line 4-4 of FIG. 1, a cylindrical lightening portion 7b is formed at the central portion of one side surface 7a of the input plate 7 facing the differential case 2. The balancer 13 connected to the central shaft 5a of the eccentric shaft 5 is disposed in the lightening portion 7b. A central axis portion of the eccentric shaft 5 so that the balancer 13 rotates around the first rotation axis X1 at a phase shifted 180 degrees from the phase of the center of gravity G1 of the first differential plate 3 revolving around the first rotation axis X1. The arm portion 13a extends radially outward from the outer periphery of 5a in the direction opposite to the projecting direction of the eccentric shaft portion 5b, and the weight portion 13b connected to the tip of the arm portion 13a. The outer periphery of the weight portion 13b is An arc shape is formed along the inner circumference of the lightening portion 7b and is adjacent to the inner circumference of the lightening portion 7b. As a result, the weight portion 13b can be disposed at a position farthest from the central shaft portion 5a in the lightening portion 7b without contacting the inner periphery of the lightening portion 7b.

The balancer 13 is preferably formed integrally with the central shaft 5 a of the eccentric shaft 5, but may be formed separately. Further, it is desirable to make the unbalance amount of the first differential plate 3 and the unbalance amount of the balancer 13 the same amount, but it is difficult to make the amount the same completely. The difference between the unbalanced amount of the moving plate 3 and the unbalanced amount of the balancer 13 is less than one-hundredth of the unbalanced amount of the first differential plate 3. That is, assuming that the mass of the first differential plate 3 is M1, the mass of the balancer 13 is M2, and as shown in FIG. 4, from the first rotation axis X1 as viewed on the projection plane orthogonal to the first rotation axis X1. The distance from the center of gravity G1 of the first differential plate 3 (the position of the center of gravity G1 on the projection plane and the position of the second rotation axis X2 generally coincide substantially) is e1, from the first rotation axis X1 When the distance to the center of gravity of the balancer 13 is e2,
| M1 × e1-M2 × e2 | <M1 × e1 / 100
By setting this, it is possible to optimize the mass M2 and the eccentricity e2 of the balancer 13 with respect to the mass M1 and the eccentricity e1 of the first differential plate 3.

  Further, the ring gear 14 is fixed to the outer periphery of the input plate 7 with a bolt B2 so as to be offset to the cover 9 side, and the differential case 2 meshes the ring gear 14 with an output gear of the transmission (not shown). As it rotates, it receives the rotation and rotates around the first rotation axis X1.

  The inner periphery of the central shaft portion 5a of the eccentric shaft 5 on the first shaft 6 side and the inner periphery of the central shaft 4b of the second differential plate 4 on the second shaft 8 side include the central shaft portion 5a and the central shaft The outer periphery of the first output shaft 15 and the outer periphery of the second output shaft 16 are respectively spline-fitted in order to rotate around the first rotation axis X1 together with 4b. The first and second output shafts 15 and 16 respectively extend to the left and right of the differential case 2 and are connected to driving wheels of a vehicle (not shown). Further, oil seals 17 and 17 'are respectively interposed between the first and second output shafts 15 and 16 and the transmission case 1 to prevent the oil in the transmission case 1 from flowing out. .

  As shown in FIG. 2 and FIG. 3 which is a cross-sectional view taken along line 3-3 of FIG. 1, one side 7 a of the input plate 7 facing the first differential plate 3 is a hypocycloid of a first wave number Z1. A first hypo groove H1 extending in the circumferential direction along the curve is formed, and one side 3a of the first differential plate 3 facing the input plate 7 is along the epicycloid curve of the second wave number Z2. A first epi-groove portion E1 extending in the circumferential direction is formed, and a plurality of first rolling balls 18 are held between the two groove portions at a portion where the both groove portions H1 and E1 overlap each other. Also, as shown in the schematic view of FIG. 2 and FIG. 5 which is a cross-sectional view taken along the 5-5 arrow of FIG. 1, the other side surface 3b of the first differential plate 3 facing the second differential plate 4 The second hypo groove portion H2 extending in the circumferential direction along the hypocycloid curve of the third wave number Z3 is formed in the second differential plate 4, and one side surface 4a of the second differential plate 4 opposite to the first differential plate 3 is formed. A second epi groove E2 extending in the circumferential direction is formed along the epicycloidal curve of the fourth wave number Z4, and a plurality of second groove portions H2 and E2 overlap each other between the two groove portions. 2 The rolling balls 19 are held.

  The first and second hypo groove portions H1 and H2 may extend in the circumferential direction along the hypotrochoid curves of the first wave number Z1 and the third wave number Z3. The groove portions E1 and E2 may extend in the circumferential direction along the epitrochoid curve of the second wave number Z2 and the fourth wave number Z4. When the groove portions H1, H2, E1 and E2 extend in the circumferential direction along the trochoid curve, the trochoid coefficients of the first hypo groove portion H1 and the first epi groove portion E1, and the second The trochoidal coefficients of the hypo groove portion H2 and the second epi groove portion E2 may be made different.

  When the first output shaft 15 is rotated with the differential case 2 fixed, the eccentric shaft 5b is rotated by the rotation of the central shaft 5a of the eccentric shaft 5, and the first differential plate 3 is moved to the first rotation axis X1. At this time, while the input plate 7 of the differential case 2 is in a fixed state, the first hypo groove portion H1 formed on one side surface 7a of the input plate 7 and one of the first differential plate 3 are rotated. Since the plurality of first rolling balls 18 are sandwiched between the first epi-groove portion E1 formed in the side surface 3a, the first differential plate 3 is formed by the second rotational axis X2 of the eccentric shaft portion 5b. It revolves around the first rotation axis X1 while rotating around. At this time, between the second hypo groove portion H2 formed on the other side surface 3b of the first differential plate 3 and the second epi groove portion E2 formed on one side surface 4a of the second differential plate 4 Also, since the plurality of second rolling balls 19 are held, the second differential plate 4 rotates around the first rotation axis X1 in conjunction with the rotation and revolution of the first differential plate 3, thereby Although the first and second output shafts 15 and 16 rotate at different rotational speeds, the first to fourth wave numbers Z1 to Z4 are Z1 = 8, Z2 = Z3 = 6, Z4 = 4, or Z1 = Since Z4 = 6, Z2 = 4, and Z3 = 8, the reduction ratio when transmitting the rotation of the first output shaft 15 to the second output shaft 16 is -1 in any case. Therefore, when the first output shaft 15 is rotated n times, the second output shaft 16 is rotated n times in the opposite direction. In this state, when the transmission is given rotational force to rotate the input plate 7 of the differential case 2 The first output shaft 15 is rotated at a rotation number n larger than the rotation number of the input plate 7, and the second output shaft 16 is rotated at a rotation number n smaller than the rotation number of the input plate 7. Thus, differential rotation can be realized such that the increase in the rotational speed of one output shaft is equal to the decrease in the rotational speed of the other output shaft. When there is no differential rotation between the first and second output shafts 15, 16, the number of rotations of the first and second output shafts 15, 16 becomes equal to the number of rotations of the input plate 7, Since the second output shafts 15 and 16 rotate integrally with the input plate 7, the first and second output shafts 15, 16 may not be provided if there is no difference in rotational speed between the first and second output shafts 15 and 16. 16 can be rotated integrally with the input plate.

  Next, the reason why equal torque can be distributed by setting the first wave number Z1 to the fourth wave number Z4 like this will be described for the case where each groove portion H1, H2, E1, E2 extends along a cycloid curve. Do.

  FIG. 6 shows a skeleton diagram of the first embodiment of the present invention when Z1 = 8, Z2 = Z3 = 6, Z4 = 4, and FIG. 7 shows Z1 = Z4 = 6, Z2 = 4. , Z3 = 8 is a skeleton diagram of the first embodiment of the present invention, but for the convenience of explanation, each groove portion is represented by the equivalent reference pitch circle.

  Assuming that the numerical values of Z1 to Z4 in FIG. 6 and FIG. 7 are not yet set to the above values, these numerical values are set to Z1 = 8, Z2 = Z3 = 6, Z4 = 4, or Z1 = Z4 = 6, The reason why equal torque distribution can be performed by setting Z2 = 4 and Z3 = 8 will be described below.

  Now, the radius of the reference pitch circle P1 of the hypocycloid curve of one side 7a of the input plate 7 in FIG. 6 or 7 is R1, and the reference pitch of the epicycloid curve of one side 3a of the first differential plate 3 facing this. The radius of the circle P2 is R2, the radius of the reference pitch circle P3 of the hypocycloid curve of the other side 3b of the first differential plate 3 is R3, the epicycloid curve of the one side 4a of the second differential plate 4 opposite this The radius of the reference pitch circle P4 is R4, and the eccentricity amount of the first differential plate 3 with respect to the input plate 7 (or the first and second output shafts 15 and 16) is C.

In FIG. 6 or 7, assuming that torque Tin is applied to the input plate 7 from the transmission, a force F1 acts on the contact portion between the reference pitch circle P1 and the reference pitch circle P2 by the torque Tin and the reference pitch circle P3. If force F2 acts on the contact portion with reference pitch circle P4 and torque TL is applied to first output shaft 15 by these forces F1 and F2 and torque TR is applied to second output shaft 16, then
Tin = F1 · R1 (1)
TR = F2 · R4 (2)
And from the moment balance of the planetary mechanism,
Tin = TL + TR (3)
Is true.

Here, in order to achieve equal torque distribution, TL = TR (4)
(3) and (4) because
Tin = 2TR (5)
Is true.

Here, further, from the balance of moments in the first differential plate,
F1 · R2 = F2 · R3 (6)
The equation (6) is
F2 = (F1 · R2) / R3 (7)
(2) and (7) because
TR = (F1 · R2 · R4) / R3 ... (8)
It can be expressed.
Substituting equations (1) and (8) on both sides of equation (5),
F1 · R1 = 2 {(F1 · R2 · R4) / R3} (9)
However, after dividing both sides of equation (9) by F1, multiplying both sides by R3 yields equation (9) as follows:
R1 · R3 = 2 (R2 · R4) (10)
Can be deformed. As apparent from FIG. 6 here,
R1 = R2 + C (11)
R3 = R4 + C (12)
Therefore, by substituting the equations (11) and (12) into the equation (10),
(R2 + C) (R4 + C) = 2 (R2 · R4) (13)
Can be obtained by transforming
R2 · R4-R2 · C- R4 · C = C 2 ··· (14)
Is obtained.

  That is, in FIG. 6 or 7, in order to achieve equal torque distribution, equation (14) must hold. In the case of a cycloid curve, the trochoid coefficient described later is 1, so it is impossible to set the number of teeth unless R1 to R4 are integers. Therefore, C, R2, and R4 must be integer values that satisfy Eq. (14).

Here, if the eccentricity amount C is C = 1 for simplicity, the equation (14) is
R2, R4-R2-R4 = 1 (15)
The integer solutions of R2 and R4 that satisfy Eq. (15) are
R2 = 3, R4 = 2 ... (pattern 1)
R2 = 2, R4 = 3 ... (pattern 2)
There are only two patterns of.

  Here, if R2 = 3 and R4 = 2 as in pattern 1, R1 = 4 and R3 = 3 from equations (11) and (12), and R2 = 2 and R4 = 3 as in pattern 2. For example, R1 = 3 and R3 = 4 according to the equation, but if R1 to R4 are set to these values, F1 = F2 according to equation (6), and from equations (1) and (2) The equation (5) and the equation (3) make it possible to establish the equation (4), that is, TL = TR.

  Next, as in pattern 1, when R1 = 4, R2 = R3 = 3, R4 = 2, Z1 = 8, Z2 = Z3 = 6, Z4 = 4, and as in pattern 2, R1 = R4 = 3, R2 = The case where Z1 = Z4 = 6, Z2 = 4, Z3 = 8 when 2, R3 = 4 will be described for the case where each groove H1, H2, E1, E2 extends along the cycloid curve. .

  In general, a relation m = d / Z holds between wave number Z, reference pitch circle diameter d and module m, and a relation C = α between eccentricity C, module m and trochoid coefficient α. Since m is satisfied, in the cycloid curve, since the trochoid coefficient α is 1, C = 1 · m = m.

Therefore, according to these relationships, in the case of a cycloid curve,
C = d / Z (16)
Is obtained, but since C = 1, 1 = d / Z, that is,
1 = 2R1 / Z1 = 2R2 / Z2 = 2R3 / Z3 = 2R4 / Z4
(17)
Is true.

  Therefore, substituting R1 = 4, R2 = R3 = 3, R4 = 2 into equation (17) gives Z1 = 8, Z2 = Z3 = 6, Z4 = 4, and R1 = R4 = 3, R2 = 2 , R4 = 4 gives Z1 = Z4 = 6, Z2 = 4, Z3 = 8. Therefore, Z1 = 8, Z2 = Z3 = 6, Z4 = 4 or Z1 = Z4 = 6, Z2. If it is set as 4 = 4 and Z3 = 8, equation (15) is established, and equal torque distribution becomes possible.

Note that (14) when the C 2 or more integer k even, integer solutions of R2, R4 to hold the R2 · R4-R2 · k- R4 · k = k 2 in formula,
R2 = 3k, R4 = 2k ... (pattern 1)
R2 = 2 k, R4 = 3 k ... (pattern 2)
In the case of pattern 1, R1 = 4k, R2 = R3 = 3k, R4 = 2k, and in the case of pattern 2, R1 = R4 = 3k, R2 = 2k, R3 = 4k. However, C in equation (16) also becomes k at this time, and equation (17) becomes k = 2R1 / Z1 = 2R2 / Z2 = 2R3 / Z3 = 2R4 / Z4, so C is an integer of 2 or more. Even in the case of pattern 1, Z1 = 8, Z2 = Z3 = 6, Z4 = 4, and in the case of pattern 2, Z1 = Z4 = 6, Z2 = 4, Z3 = 8.

  Next, the case where the groove portions H1, H2, E1, and E2 extend along the trochoid curve will be described. Equation (17) is transformed as follows.

1 = 2 R 1 · α 1 / Z 1 = 2 R 2 · α 1 / Z 2 = 2 R 3 · α 2 / Z 3 =
2R4 · α 2 / Z 4 · · · (18)
Here, α1 represents trochoid coefficients for the reference pitch circles P1 and P2, and α2 represents trochoid coefficients for the reference pitch circles P3 and P4.

  Therefore, if an arbitrary value is set in the range of 0 to 1 for each of the trochoid coefficients α1 and α2, the number of teeth Z is an integer and the eccentricity C is common, while the radius R1, R2 and R3 of the reference pitch circle , R 4 can be designed to an optimal size considering strength and dimensions. The number of teeth can be Z1 = 8, Z2 = Z3 = 6, Z4 = 4 in the case of pattern 1, and Z1 = Z4 in the case of pattern 2. = 6, Z2 = 4, and Z3 = 8.

  Next, the operation of the first embodiment will be described.

  The first differential plate 3 and the first differential plate 3 are disposed adjacent to one side of the input plate 7 and the cycloid reduction mechanism or trochoid reduction mechanism that constitutes the differential device is rotated about the first rotation axis X1. A second differential plate 4 disposed adjacent to one side opposite to the input plate 7 and the first differential plate 3 rotatably supported about a second rotation axis X2 eccentric to the first rotation axis X1 The eccentric shaft 5 is integrally rotatably connected to the first output shaft 15, and the second differential plate 4 is integrally rotatably connected to the second output shaft 16. A first hypo groove portion H1 extending in a circumferential direction along a hypocycloid curve or a hypotrochoid curve of a first wave number Z1 is formed on one side surface 7a of the input plate 7 facing the first differential plate 3; The first wave plate Z2 has a second wave number Z2 on one side 3a of the differential plate 3 facing the input plate 7 A first epi-groove portion E1 extending circumferentially along a piccloid curve or an epitrochoid curve is formed, and a plurality of first groove portions H1 and E1 are formed between the two groove portions H1 and E1 in a portion where these groove portions H1 and E1 overlap each other. The rolling ball 18 is held, and the other side surface 3b of the first differential plate 3 opposite to the second differential plate 4 is circumferentially along the hypocycloid curve or the hypotrochoid curve of the third wave number Z3. An extending second hypo groove portion H2 is formed, and the side surface 4a of the second differential plate 4 facing the first differential plate 3 is surrounded along the epicycloid curve or epitrochoid curve of the fourth wave number Z4. A second epi-groove portion E2 extending in the direction is formed, and a plurality of second rolling balls 19 are held between the two groove portions H2 and E2 at a portion where these two groove portions H2 and E2 mutually overlap. 1st to 4th The first wave number Z1 is 8, the second wave number Z2 and the third wave number Z3 are both 6, and the fourth wave number Z4 is 4, or both the first wave number Z1 and the fourth wave number Z4 are 6. Since the second wave number Z2 is 4 and the third wave number Z3 is 8, when the input plate 7 is rotated, there is no difference in rotational speed between the first and second output shafts 15 and 16. Is capable of integrally rotating the first and second output shafts 15 and 16 with the input plate 7 and providing a rotation speed difference between the first and second output shafts 15 and 16, the rotation speed of one of the output shafts A differential mechanism capable of equalizing the torque difference with equal rotation of the other output shaft, etc. can be realized without using bevel gears or center plates with radial slots. Therefore, the axial length of the differential mechanism can be suppressed to make it compact, and there is no generation of rattling noise as in the case of using a bevel gear, and the radial elongated holed center which causes the rolling ball to slide Since the plate is unnecessary, the power from the input plate 7 can be efficiently transmitted to the first and second output shafts 15 and 16. Still further, the first and second rolling balls 18, 19 are disposed between the first hypo groove portion H1 and the first epi groove portion E1, and the second hypo groove portion H2 and the second epi groove portion. Since torque is distributed and transmitted between E2 and E2, the torque transmitted by each rolling ball 18, 19 can be reduced, and the strength and durability performance of each rolling ball 18, 19 is improved.

  When the first and second hypo grooves H1 and H2 and the first and second epi grooves E1 and E2 extend in the circumferential direction along the trochoid curve, the first hypo grooves H1 are formed. The trochoid coefficient of the first epi-groove portion E1 may be different from the trochoid coefficient of the second hypo-groove portion H2 and the second epi-groove portion E2. For example, the trochoid coefficient on the side of the second rolling ball 19 with a small number of rolling balls is reduced to increase the pitch circle radius and the ball diameter, whereby the load sharing per ball can be reduced and the strength is increased. An optimal design can be made in consideration of the weight and weight reduction.

  Moreover, at that time, a cylindrical lightening portion 7b is formed in the central portion of one side surface 7a of the input plate 7, and in the lightening portion 7b, the first differential plate 3 which rotates around the first rotation axis X1. Since the balancer 13 which rotates around the first rotation axis X1 with a phase shifted 180 degrees from the phase of the center of gravity is disposed, the unbalanced rotation of the center of gravity of the first differential plate 3 which rotates around the first output shaft 15 is It can be canceled by 13 and the vibration due to the centrifugal force due to the unbalanced amount of the first differential plate 3 and the generation of the noise accompanying it can be effectively suppressed. Further, by arranging the balancer 13 in the lightening portion 7b of the input plate 7, the balancer 13 can be compactly arranged between the first differential plate 3 and the input plate 7, and an unnecessary portion of the input plate 7 is obtained. Of the material can be reduced by the lightening portion 7b, so that the cost of the differential device D can be reduced and the weight of the differential device D can be reduced.

  Further, a differential case 2 rotatably supported around a first rotation axis X1 on a transmission case 1 of a car is fixed to the input plate 7 and the input plate 7 so that a first differential plate 3, an eccentric shaft 5 and Since the cover 9 covers the second differential plate 4, the two-stage transmission mechanism using the cycloid reduction mechanism or the trochoid reduction mechanism is a differential that allows the rotational difference between the left and right or front and rear drive wheels of the vehicle. It can be suitably used as an apparatus. Moreover, since the input plate 7 constitutes a part of the differential case 2, the number of parts can be reduced, and the first and second differential plates 3 and 4 and the eccentric shaft 5 are provided in the differential case 2. As it is housed, such a new mechanism of the automotive differential can be made compact without largely changing the configuration of the conventional differential.

  Moreover, the eccentric shaft 5 projects radially from the central shaft portion 5a, which rotates around the first rotation axis X1, and the central shaft portion 5a, so that the first differential plate 3 can be rotated around the second rotation axis X2. And the central shaft 5a is connected to the first output shaft 15 through the central portion of the input plate 7 and the second differential plate 4 has a first rotation. It has a central axis 4b that rotates around the axis X1, and the central axis 4b penetrates the central portion of the cover 9 and is connected to the second output shaft 16. The first differential plate 3 is supported by the eccentric shaft portion 5b of the eccentric shaft 5 penetrated through the first portion, and the central shaft 4b is penetrated through the central portion of the cover 9 outward of the first differential plate 3. The eccentric shaft 5, the first differential plate 3 and the second differential plate 4 can be easily assembled in the differential case 2 simply by arranging the differential plate 4. .

  The input plate 7 and the cover 9 have hollow cylindrical first and second shafts 6 and 8 rotatably supported by the transmission case 1 on the first rotation axis X 1. The central shaft portion 5 a is rotatably supported on the inner periphery of the first shaft 6 via the first bearing 11, and the central shaft 4 b of the second differential plate 4 is formed on the inner periphery of the second shaft 8. In the circular recess 4 c formed on one side surface 4 a of the second differential plate 4 so as to be rotatably supported via the bearing 11 ′ of the second embodiment. Since the third bearing 11 ′ ′ is engaged with the first bearing 11 ′ ′, smooth relative rotation of the eccentric shaft 5 and the second differential plate 4 in the differential case 2 can be ensured only by the first to third bearings 11 to 11 ′ ′. .

  Moreover, the lightening portion 7b of the input plate 7 is formed in a cylindrical shape, and in the lightening portion 7b, it is 180 degrees out of phase with the phase of the center of gravity G1 of the first differential plate 3 rotating around the first rotation axis X1. The balancer 13 connected to the eccentric shaft 5 is disposed so as to rotate around the first rotation axis X1 at a phase that is different from the unbalanced rotation of the first differential plate 3 rotating around the first rotation axis X1. Therefore, the vibration due to the centrifugal force due to the unbalanced amount of the first differential plate 3 and the generation of the noise associated therewith can be effectively suppressed. Moreover, since the balancer 13 is accommodated in the lightening portion 7b of the input plate 7 constituting a part of the differential case 2 and disposed in the differential case 2, the differential case 2 does not interfere with the other members. It can be arranged compactly at the optimum position inside, and the differential case 2 will not be upsized.

  In addition, the mass of the first differential plate 3 is M1, the mass of the balancer 13 is M2, and the first differential plate 3 is viewed from the first rotation axis X1 when viewed from the projection plane orthogonal to the axis of the first output shaft 15. Since the distance from the first rotation axis X1 to the center of gravity G2 of the balancer 13 is e2 since the distance to the center of gravity G1 of the frame is e1, | M1 × e1−M2 × e2 | <M1 × e1 / 100, The unbalance amount of the differential plate 3 and the unbalance amount of the balancer 13 can be made substantially the same, and the mass and the eccentricity of the balancer 13 with respect to the mass and the eccentricity of the first differential plate 3 can be optimized.

  Furthermore, the eccentric shaft 5 projects radially from the central shaft portion 5a, which rotates around the first rotation axis X1, and the central shaft portion 5a, to rotate the first differential plate 3 around the second rotation axis X2. An arm portion 13a having an eccentric shaft portion 5b capable of being supported, the balancer 13 extending radially outward from the outer periphery of the central shaft portion 5a of the eccentric shaft 5 in the direction opposite to the projecting direction of the eccentric shaft portion 5b; The weight portion 13b is connected to the tip end of the arm portion 13a, and the outer periphery of the weight portion 13b is formed in an arc shape along the inner periphery of the lightening portion 7b and is adjacent to the inner circumference of the lightening portion 7b Therefore, it is possible to move the center of gravity of the balancer 13 away from the rotation center of the balancer 13 by bringing the weight portion 13b of the balancer 13 as close as possible to the inner peripheral surface of the lightening portion 7b, thereby suppressing an increase in weight due to the balancer 13. it can.

  In addition, the differential case 2 rotatably supported around the first rotation axis X1 in the transmission case 1 of the automobile is fixed to the input plate 7 and the input plate 7 so that the first differential plate 3 and the eccentric shaft 5 are fixed. And the cover 9 covering the balancer 13 and the second differential plate 4 so that the two-stage transmission mechanism using the cycloid reduction mechanism is a differential that allows the rotational difference between the left and right or front and rear drive wheels of the vehicle. While being suitably used as an apparatus, since the input plate 7 constitutes a part of the differential case 2, the number of parts can be reduced. In addition, since the first, second and third differential plates 3, 4 and the eccentric shaft 5 can be compactly accommodated in the differential case 2 by arranging the balancer 13 in the lightening portion 7b of the input plate 7, such a new The mechanical differential of the vehicle can be formed without significantly changing the configuration of the conventional differential.

  The input plate 7 and the cover 9 have hollow cylindrical first and second shafts 6 and 8 rotatably supported by the transmission case 1 on the first rotation axis X 1. The central shaft portion 5 a is rotatably supported on the inner periphery of the first shaft 6 via the first bearing 11, and the central shaft 4 b of the second differential plate 4 is on the inner periphery of the second shaft 8. A circular recess 4 c rotatably supported via a second bearing 11 ′ and having a central shaft portion 5 a of the eccentric shaft 5 opposite to the first shaft 6 formed on one side surface of the second differential plate 4 As it is fitted inside via the third bearing 11 ′ ′, smooth relative rotation of the eccentric shaft 5 and the second differential plate 4 in the differential case 2 is ensured only by the first to third bearings 11 to 11 ′ ′. The operation of assembling the cycloid reduction mechanism into the differential case 2 is also facilitated.

  Furthermore, when the balancer 13 is integrally formed with the central shaft portion 5a of the eccentric shaft 5, the positional relationship between the balancer 13 and the eccentric shaft 5 does not change in any case. 1) It can be rotated with a phase which is 180 degrees out of phase with the center of gravity of the differential plate 3.

Second embodiment

  Next, a second embodiment in which the differential gear of the present invention is used as a differential gear of a car will be described based on FIG.

  In the second embodiment described in FIG. 8, the sub-balancer 20 is added to the differential device of the first embodiment, and a first difference is provided at the central portion of one side surface 4 a of the second differential plate 4. A cylindrical auxiliary lightening portion 4d is formed opposite to the lightening portion 7b of the input plate 7 with the moving plate 3 interposed therebetween, and the first difference in that it revolves around the first rotation axis X1 in the auxiliary lightening portion 4d. The differential gear of the first embodiment is only in that the sub balancer 20 connected to the eccentric shaft 5 is arranged to rotate around the first rotation axis X1 with a phase shifted 180 degrees from the phase of the center of gravity of the moving plate 3 Are the same as those of the differential device of the first embodiment in the other respects, portions in FIG. 8 which are not different from the first embodiment are denoted by the same reference numerals as in the first embodiment, and The description of the parts is omitted.

In FIG. 8, the above-described sub-thinned portion 4 d is formed at the central portion of the one side surface 4 a of the second differential plate 4, and the center G1 of the first differential plate 3 is formed in the sub-thinned portion 4 d. The sub balancer 20 connected to the central shaft portion 5a of the eccentric shaft 5 on the second differential plate 4 side is disposed so as to rotate around the first rotation axis X1 with a phase shifted 180 degrees from the phase. Although it is desirable to equalize the sum of the unbalance amount of the first differential plate 3 and the unbalance amount of the balancer 13 and the sub-balancer 20, it is difficult to make the same amount completely. The difference between the unbalance amount of the first differential plate 3 and the sum of the unbalance amounts of the balancer 13 and the sub-balancer 20 is less than 1/100 of the unbalance amount of the first differential plate 3. That is, the first rotation axis X1 when viewed from the projection plane orthogonal to the axis of the first output shaft 15 with the mass of the first differential plate 3 as M1, the mass of the balancer 13 as M2, and the mass of the sub balancer 20 as M3. The distance from the first rotation axis X1 to the center of gravity G2 of the balancer 13 is e2. The center of gravity G3 of the sub balancer 20 from the first rotation axis X1 (where G3 is illustrated) When the distance to e) is e3
| M1 × e1- (M2 × e2 + M3 × e3) | <M1 × e1 / 100
By doing this, the amount of imbalance of the first differential plate 3 and the sum of the amounts of imbalance of the balancer 13 and the sub-balancer 20 can be made substantially the same, and the mass M1 of the first differential plate 3 and the eccentricity e1 The mass M2, M3 and eccentricity e2, e3 of the balancer 13 and the sub-balancer 20 can be optimized.

  The sub-balancer 20 has substantially the same shape as the balancer 13, and extends from the outer periphery of the central shaft 5a of the eccentric shaft 5 radially outward in the direction opposite to the direction in which the eccentric shaft 5b protrudes. The outer periphery of the weight portion 20b is formed in an arc shape along the inner periphery of the auxiliary thinning portion 4d and is adjacent to the inner periphery of the auxiliary thinning portion 4d. . As a result, the weight portion 20b can be disposed at a position farthest from the first output shaft 15 in the auxiliary lightening portion 4d without coming into contact with the inner periphery of the auxiliary lightening portion 4d.

  Next, the operation of the second embodiment will be described.

  In the center of one side surface 4a of the second differential plate 4, a circular sub-thinned portion 4d is formed opposite to the thinned portion 7b of the input plate 7 with the first differential plate 3 interposed therebetween. The sub balancer connected to the eccentric shaft 5 so as to rotate around the first rotation axis X1 at a phase shifted 180 degrees from the phase of the center of gravity of the first differential plate 3 rotating around the first rotation axis X1 in the portion 4d 20 are arranged, so that the unbalanced rotation of the first differential plate 3 can be balanced in a balanced manner from the left and right by the balancers 13 and the sub-balancer 20 disposed on both sides of the first differential plate 3, While being able to suppress more effectively generation | occurrence | production of the vibration resulting from the centrifugal force by the unbalance amount of the board 3, each mass of the balancer 13 and the sub-balancer 20 can be made small, and they can be made compact.

  Further, the difference between the imbalance amount of the first differential plate 3 and the sum of the imbalance amounts of the balancer 13 and the sub-balancer 20 is a small value less than 1/100 of the imbalance amount of the first differential plate 3. Therefore, the imbalance amount of the first differential plate 3 and the sum of the imbalance amounts of the balancer 13 and the sub-balancer 20 can be made substantially the same, and the balancer for the mass M1 and the eccentricity e1 of the first differential plate 3 The masses M2 and M3 and the eccentric amounts e2 and e3 of the secondary balancer 20 and the secondary balancer 20 can be optimized.

  Further, the sub-balancer 20 includes an arm 20a extending radially outward from the outer periphery of the central shaft 5a of the eccentric shaft 5 in the direction opposite to the projecting direction of the eccentric shaft 5b, and a weight 20b connected to the tip of the arm 20a. , And the outer periphery of the weight portion 20b is formed in an arc shape along the inner periphery of the auxiliary thinned portion 4d and is adjacent to the inner periphery of the auxiliary thinned portion 4d. As close as possible to the inner peripheral surface of the auxiliary thin portion 4d, the center of gravity of the auxiliary balancer 20 can be separated from the rotation center of the auxiliary balancer 20, and an increase in weight due to the auxiliary balancer 20 can be suppressed.

  Furthermore, when the sub-balancer 20 is integrally formed with the central shaft portion 5 a of the eccentric shaft 5, the positional relationship between the sub-balancer 20 and the eccentric shaft 5 in the circumferential direction does not shift. The first differential plate 3 can be rotated with a phase that is 180 degrees out of phase with the center of gravity.

Third embodiment

  Next, a third embodiment of the present invention will be described based on FIG.

  In the third embodiment, the first differential plate 3 in FIG. 1 is configured by a pair of rotating plates 3c and 3d connected integrally rotatably via a connecting member 3e.

  That is, in the third embodiment, one side of the first rotary plate 3 c faces one side 7 a of the input plate 7 and one side of the second rotary plate 3 d faces one side 4 a of the second differential plate 4. The other side surface of the first rotary plate 3c and the other side surface of the second rotary plate 3d are mutually spaced apart by a plurality of rod-like connecting members 3e arranged at equal intervals in the circumferential direction on the outer peripheral portion thereof. Are connected. Further, a first epi groove portion E1 facing the first hypo groove portion H1 of the input plate 7 is formed on the one side surface of the first rotary plate 3c, and on the one side surface of the second rotary plate 3d. Is formed with a second hypo groove portion H2 opposed to the second epi groove portion E2 of the second differential plate 4 and between the both groove portions H1 and E1 in a portion where both groove portions H1 and E1 overlap each other A plurality of first rolling elements 18 are sandwiched, and a plurality of second rolling elements 19 are sandwiched between the two groove portions H2 and E2 at a portion where the two groove portions H2 and E2 overlap each other. The other configuration is the same as that of the first embodiment, and therefore, in FIG. 9, portions corresponding to those of the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. The third embodiment is also applicable to the first differential plate 3 of the second embodiment.

  Next, the operation of the third embodiment will be described.

  In the third embodiment, since the first differential plate 3 is configured to include the pair of rotatable plates 3c and 3d which are mutually connected at an interval by the rod-like connecting member 3e and are integrally rotatable, the first difference The moving plate 3 can be divided into two rotating plates 3c and 3d. Therefore, for example, since it is possible to adopt a manufacturing method in which two rotary plates 3c, 3d each having a groove portion on one side are formed by forging etc. and then connected by the rod-like connecting member 3e, the groove portion E1 excellent in strength , H2 can be formed quickly and easily, and the manufacturing workability is increased. Further, since the sizes of the surface of the first differential plate 3 facing the input plate and the surface of the first differential plate 3 facing the second differential plate can be set independently of each other, the second wave number is 4 and the third wave number is 8 In this case also, the freedom of design is improved.

  Furthermore, since a gap is formed between the two rotary plates 3c and 3d, the balancer 13 connected to the eccentric shaft 5 is disposed in the gap instead of being disposed in the lightening portion 7b of the input plate 7. It can also be done.

  As mentioned above, although 1st-3rd embodiment of this invention was described, this invention can perform various design changes in the range which does not deviate from the summary.

  For example, although the balancer is used in the first to third embodiments, the balancer may be omitted.

  In the present invention, although the differential gear is applied to the differential gear accommodated in the transmission case 1 to allow the rotational difference between the left and right or front and rear drive wheels of the automobile, the differential gear of the present invention It is not limited to differentials.

In the above embodiment, if the first and second hypo groove portions H1 and H2 and the first and second epi groove portions E1 and E2 extend in the circumferential direction along the cycloid curve, the hypo The hypo streak groove extending along the cycloid curve may be a modification of a portion of the hypocycloid curve, and the epi streak groove extending along the epicycloid curve may also be a modification of a portion of the epicycloid curve. It may be. For example, only the pole PO connecting the waves and the waves may be modified, and the other part may be configured to satisfy the geometric condition of the cycloid curve.

Claims (12)

The first output shaft (15) and the second output shaft (16) are arranged so as to be relatively rotatable on the first rotation axis (X1) through the cycloid reduction mechanism or the trochoid reduction mechanism of the rotational force of the input plate (7) A differential that distributes
The speed reduction mechanism includes a first differential plate (3) disposed adjacent to one side of the input plate (7) rotating around the first rotation axis (X1), and the first differential plate (3). The second differential plate (4) disposed adjacent to the one side opposite to the input plate (7) and the first differential plate (3) are eccentric from the first rotation axis (X1) And an eccentric shaft (5) rotatably supported about a second rotation axis (X2), the eccentric shaft (5) being integrally rotatably connected to the first output shaft (15), the second difference The movable plate (4) is integrally rotatably connected to the second output shaft (16),
A first side (7a) of the input plate (7) facing the first differential plate (3), a first extending in a circumferential direction along a hypocycloid curve or a hypotrochoid curve of a first wave number (Z1) The epicyclic curve or the epi of the second wave number (Z2) is formed on one side surface (3a) of the first differential plate (3) facing the input plate (7). A first epi-groove (E1) extending circumferentially along the trochoid curve is formed, and a plurality of first epi-grooves (H1, E1) overlap each other between the two grooves (H1, E1). The first wave plate (Z3) is placed on the other side surface (3b) of the first differential plate (3) opposite to the second differential plate (4) while the first rolling element (18) is held. A second circumferentially extending along a cycloid or hypotrochoid curve The epicyclic curve of the fourth wave number (Z4) is formed on one side surface (4a) of the second differential plate (4) on which the hypo groove portion (H2) is formed and which faces the first differential plate (3). Alternatively, a second epi groove (E2) extending circumferentially along the epitrochoid curve is formed, and a plurality of these grooves (H2, E2) overlap each other between the two grooves (H2, E2). The second rolling element (19) of
The first wave number (Z1) is 8, the second wave number (Z2) and the third wave number (Z3) are both 6, and the fourth wave number (Z4) is 4, or A differential device characterized in that the wave number (Z1) and the fourth wave number (Z4) are both 6, the second wave number (Z2) is 4, and the third wave number (Z3) is 8. In the differential according to claim 1,
A differential case (2) rotatably supported around the first rotation axis (X1) in a transmission case (1) of an automobile is fixed to the input plate (7) and the input plate (7) to be mounted A differential device comprising: 1 differential plate (3), a cover (9) covering the eccentric shaft (5) and the second differential plate (4). In the differential according to claim 2,
A central shaft portion (5a) that rotates the eccentric shaft (5) around the first rotation axis (X1), and a radial direction that protrudes from the central shaft portion (5a), the first differential plate (3) And the eccentric shaft (5b) rotatably supporting the second rotation axis (X2), the central shaft (5a) penetrates the central portion of the input plate (7) and Connected to the first output shaft (15), the second differential plate (4) has a central axis (4b) that rotates around the first rotation axis (X1), the central axis (4b) being A differential device, wherein the central portion of the cover (9) is penetrated and connected to the second output shaft (16). In the differential according to claim 3,
The hollow cylindrical first and second shafts rotatably supported on the transmission case (1) on the first rotation axis (X1), the input plate (7) and the cover (9) 6, 8), and the central shaft portion (5a) of the eccentric shaft (5) is rotatably supported on the inner periphery of the first shaft (6) via a first bearing (11). The central axis (4b) of the second differential plate (4) is rotatably supported on the inner periphery of the second shaft (8) via a second bearing (11 '); The central axis portion (5a) of the eccentric shaft (5) opposite to the shaft (6) is in a circular recess (4c) formed in the one side surface (4a) of the second differential plate (4) Differential fitted in via the third bearing (11 ′ ′). The differential device according to any one of claims 1 to 4.
A differential device characterized in that a lightening portion (7b) is formed at a central portion of the one side surface (7a) of the input plate (7). In the differential according to claim 1,
A lightening portion (7b) is formed at a central portion of the one side surface (7a) of the input plate (7), and the lightening portion (7b) rotates around the first rotation axis (X1) A balancer (13) coupled to the eccentric shaft (5) is arranged to rotate around the first rotation axis (X1) with a phase shifted 180 degrees from the phase of the center of gravity (G1) of the first differential plate (3) A differential device characterized in that it is arranged. The differential according to claim 6, wherein the mass of the first differential plate (3) is M1, the mass of the balancer (13) is M2, and the projection plane is orthogonal to the first rotation axis (X1). The distance from the first rotation axis (X1) to the center of gravity (G1) of the first differential plate (3) is e1, and the center of gravity (G2) of the balancer (13) from the first rotation axis (X1) When the distance to) is e2
| M1 × e1-M2 × e2 | <M1 × e1 / 100
A differential device characterized by being.   The differential according to claim 6 or 7, wherein the eccentric shaft (5) has a central shaft (5a) that rotates about the first rotation axis (X1), and the central shaft (5a). And an eccentric shaft (5b) which radially projects from the shaft to rotatably support the first differential plate (3) around the second rotation axis (X2), and the balancer (13) An arm (13a) extending radially outward from the outer periphery of the central shaft (5a) in the direction opposite to the projecting direction of the eccentric shaft (5b), and a weight (13b) connected to the tip of the arm (13a) , And the outer periphery of the weight portion (13b) is formed in an arc shape along the inner periphery of the lightening portion (7b).   The differential according to claim 8, characterized in that the balancer (13) is integrally formed with the central shaft (5a).   The differential according to any one of claims 6 to 9, wherein the differential case (2) rotatably supported about the first rotation axis (X1) in a transmission case (1) of a motor vehicle is the input Plate (7) and fixed to the input plate (7) to cover the first differential plate (3), the eccentric shaft (5), the balancer (13) and the second differential plate (4) And a cover (9).   The differential device according to any one of claims 6 to 10, wherein the first differential plate (3) is held at the central portion of the one side surface (4a) of the second differential plate (4). The cylindrical sub-thinned portion (4d) is formed to face the lighted portion (7b) of the input plate (7), and the first rotational axis (X1) is formed in the sub-thinned portion (4d). A sub-balancer connected to the eccentric shaft (5) so as to rotate around the first rotation axis (X1) with a phase shifted 180 degrees from the phase of the center of gravity of the first differential plate (3) rotating around). A differential device characterized in that (20) is arranged. The differential according to any one of claims 1 to 11.
A differential device characterized in that the first differential plate (3) includes a pair of rotatable plates (3c, 3d) which are mutually connected and integrally rotatable.

Images